What Causes Mouth Ulcers?

Mouth ulcers — also known as canker sores — are normally small, painful lesions that develop in your mouth or at the base of your gums. They can make eating, drinking, and talking uncomfortable. Women, adolescents, and people with a family history... Read More

Canker sores

Mouth ulcers — also known as canker sores — are normally small, painful lesions that develop in your mouth or at the base of your gums. They can make eating, drinking, and talking uncomfortable. Women, adolescents, and people with a family history of mouth ulcers are at higher risk for developing mouth ulcers.

Mouth ulcers aren’t contagious and usually go away within one to two weeks. However, if you get a canker sore that is large or extremely painful, or if it lasts for a long time without healing, you should seek the advice of a doctor.

What triggers mouth ulcers?

There is no definite cause behind mouth ulcers. However, certain factors and triggers have been identified. These include:

What symptoms are associated with mouth ulcers?

Minor

Minor canker sores are small oval or round ulcers that heal within one to two weeks with no scarring.

Major

Major canker sores are larger and deeper than minor ones. They have irregular edges and can take up to six weeks to heal. Major mouth ulcers can result in long-term scarring.

Herpetiform

Herpetiform canker sores are pinpoint size, occur in clusters of 10 to 100, and often affect adults. This type of mouth ulcer has irregular edges and will often heal without scarring within one to two weeks.

You should see a doctor if you develop any of the following:

unusually large mouth ulcers

new mouth ulcers before the old ones heal

sores that persist more than three weeks

sores that are painless

mouth ulcers that extend to the lips

pain that can’t be controlled with over-the-counter or natural medication

How are mouth ulcers diagnosed?

Your doctor will be able to diagnose mouth ulcers through a visual exam. If you’re having frequent, severe mouth ulcers, you might be tested for other medical conditions.

What are some ways to treat mouth ulcers?

Most mouth ulcers don’t need treatment. However, if you get mouth ulcers often or they’re extremely painful, a number of treatments can decrease pain and healing time. These include:

using a rinse of saltwater and baking soda

placing on the mouth ulcer

covering mouth ulcers with baking soda paste

using over-the-counter benzocaine (topical anesthetic) products like or

applying ice to canker sores

using a mouth rinse that contains a steroid to reduce pain and swelling

using topical pastes

placing damp tea bags on your mouth ulcer

taking nutritional supplements like , , , and

trying natural remedies such as , , , and root

Tips to prevent mouth ulcers

You can take steps to reduce the occurrence of mouth ulcers. Avoiding foods that irritate your mouth can be helpful. That includes acidic fruits like pineapple, grapefruit, oranges, or lemon, as well as nuts, chips, or anything spicy. Instead, choose whole grains and alkaline (nonacidic) fruits and vegetables. Eat a healthy, well-balanced diet and take a daily multivitamin.

Try to avoid talking while you’re chewing your food to reduce accidental bites. Reducing stress and maintaining good oral hygiene by using dental floss daily and brushing after meals also may help. Finally, get adequate sleep and rest. This not only will prevent mouth ulcers, but a host of other illnesses as well.

Some people find avoiding soft bristle toothbrushes and mouthwashes that contain sodium lauryl sulfate also helps. Your dentist can give you wax to cover dental or orthodontic mouth devices that have sharp edges.

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Medically reviewed by Christine Frank, DDS on December 20, 2017 — Written by Shannon Johnson